1. Field of the Invention
The present invention relates to a skateboard and to the deck of a skateboard.
2. Description of Background and Relevant Information
A skateboard is generally constituted of a deck beneath which two devices for holding an axle are fixed. Generally, each of the holding devices is directional, and the axle which they hold supports two wheels. Such devices for directional holding of an axle are commonly referred to as trucks.
The trucks make it possible to control the direction of the skateboard, while the skater has both feet positioned on the deck and moves with the latter by rolling. The control of the direction is carried out by shifting the skater""s weight to one side or the other.
The construction of these trucks is drawn from roller skates including two axles each having two wheels, i.e., so-called quad skates, and includes mainly two elements, a base plate that ensures the fixing of the truck beneath the deck and a hanger.
One of the ends of the hanger is extended along a first axis and pivots about a point located in the base plate. This end, also called the pivot, penetrates into a recess that is provided in the base plate. A second end of the hanger has a protuberance called a ring. The latter is held by means of two elastomeric pieces called buffers and a kingpin oriented along a second axis applied on the base plate. Finally, a third end of the hanger serves as a support for an axle on which two wheels are mounted, this axle being oriented along a third axis.
The orientation of the three axes of the hanger in relation to one another is such that the inclination of the deck on either of its lateral edges, i.e., along a longitudinal axis of the deck, creates a pivoting of the axle along a vertical axis. Generally speaking, the kingpin forms, together with the plane of the deck, an angle that is not a right angle.
The skateboard trucks, despite their simplicity, fulfill several functions. First, they are means for fixing the wheels to the deck which enable the skater to direct the deck. Second, the presence of the elastomeric elements produces a resistance to the forces generated by the skater to pivot the deck, and thereby prevents unexpected changes in direction. Finally, these same elastomers ensure a force for returning the axle in a neutral position after a change in direction.
The construction of skateboard decks uses several types of materials including plastic materials, wood, and composite materials, in particular. Each of these materials has specific characteristics and advantages.
For skateboarding, which involves performing numerous figures and aerial jumps, the decks entirely constructed with veneered wood are preferred. In general, seven plies of constant thickness are coated with glue before being hot pressed. This construction mode is less expensive for small scale manufacture than the molding technique. Furthermore, the decks manufactured by this process have very good dynamic characteristics.
The dynamic characteristics of a deck include, among others, what is known as the xe2x80x9cpopxe2x80x9d in the skateboarding community. Pop refers to the capacity of a deck to propel the skater in the air, after the latter exerts a substantial pressure on the rear portion of the deck. The origin of the term xe2x80x9cpopxe2x80x9d lies in the sound made by the rear end of the deck, or tail, when it touches the ground.
The various types of decks have a pop that differs not only due to their geometric characteristics, but also to the properties of their constituent materials which modify the sound produced during contact between the deck and the ground. The pop of a deck is important especially as it is the basis of one of the fundamental figures performed in skateboarding, viz., the ollie.
The decks made of veneered wood are generally preferred by skateboarders. However, these decks have numerous disadvantages. In view of their rigidity, these decks are relatively heavy. In addition, they do not resist well the wear and tear associated with normal use including that caused by abrasion during frictional contact with various surfaces with which contact is made during skateboarding. The edges of the decks become rasped after minimum use, which can present risks for the skater. Thus, when the skater grabs the deck, he/she runs the risk of being cut by a splinter.
The trucks, whose base plate is typically fixed by four screws extending through the deck, demarcate zones where the deck is weakened. So as not to hinder the displacement of the skater""s feet along the deck, the head of the screws used for fixing the trucks should not extend beyond the top surface of the deck. It is then necessary to chamfer the screw holes, which weakens the deck all the more and generates incipient breaks.
It is during jump landing that the risks of fracture are the most substantial. The deck often breaks off clean between the end thereof and the base of the truck. In most cases, the deck is sheared directly at the edge of the base of the truck.
One of the solutions to this problem consists of increasing the number of layers in the deck. In the case of a deck made of plywood, it would be necessary to add from two to four plies to the six or seven plies that are commonly used for making the deck. However, a deck having eight to eleven plies would be about 50% heavier, which would considerably limit the possibilities for aerial figures. Furthermore, it would be practically impossible to improve the pop of the deck, because it would be too rigid.
Another problem faced by the manufacturers of skateboard decks is created by the so-called xe2x80x9cslidexe2x80x9d figures performed in this sport. Indeed, numerous phases in the movement of the rider consist of sliding the deck on surfaces such as metallic rails, ledges of concrete walls, sidewalks. Reference is made to noseslide and tailslide for which the lower portion of the deck that is located between the truck and the front or rear end of the deck is in contact with the element (such as a curb, bench, handrail, table, etc.) on which one is sliding. Reference is also made to rockslide where it is the portion between the two trucks that slides on the element on which one is sliding. Of course, these practices damage the deck considerably, especially when the latter is composed of a plurality of superimposed layers, because the surface layers are quickly worn by abrasion.
In the case of a deck made of plywood and varnish, the varnish layer disappears after a few slides, and the surface layer itself erodes with each slide. Moreover, since wood has a high coefficient of friction, the slide figures lack amplitude.
It is partly to resolve this problem that it is envisioned to glue, after manufacture of the deck, metallic or plastic elements, called sliders, which protect the deck from abrasion and facilitate the slide. However, the added elements do not hold well beneath the deck.
An object of the present invention is to overcome the aforementioned disadvantages and, in particular, to propose a skateboard deck of the type including a plurality of layers whose strength is increased, and which enables better slides.
Another object of the invention is to increase the break resistance of the deck while increasing the pop thereof.
One of the objects of the invention is also to simplify the current deck/truck system so as to facilitate the assembly and holding of the trucks on the deck, and to make the entire skateboard lighter so as to increase its performance.
To this end, the invention includes a deck having a plurality of layers, at least four of which have a constant or substantially constant thickness, and which include an upper surface layer, a lower surface layer, and several intermediate layers, the deck also including at least one reinforcement arranged in the area of at least one of the zones for fixing the trucks. This reinforcement includes at least one portion which, along a transverse plane, is inserted between the upper surface layer and the lower surface layer.
Such a deck is thus more solid while preserving the advantages of a multilayer construction, especially the advantages of a veneered wood construction.
In a preferred embodiment of the invention, the reinforcements do not have a uniform cross-section. They have a profiled cross-section whose thickest zones are located in the area where the trucks are fixed.
In a preferred embodiment of the invention, the reinforcements include a projecting portion that extends through the lower surface layer, this projecting portion receiving the pivot of the hanger and having a smooth surface.
In another embodiment of the invention, the reinforcement plate is inserted between two intermediate plies and has a contour that is equivalent to the general contour of the deck.
One of the principles underlying the invention comprises inserting one or several reinforcements within the plies of the deck during the shaping step. The reinforcement(s) is (are) arranged so as to increase the resistance of the weak zones, including the tail, nose, and center. These reinforcements also contribute to the rigidity of the deck, and can be prestressed to increase the responsiveness of the deck. The material used for these inserts optimizes the weight, the rigidity and the strength of the finished deck.
Furthermore, the presence of these reinforcements does not make it absolutely necessary to bore four through holes for fixing the deck.
The invention also relates to a multi-layered deck, in which the base plate of the truck is integrated in the deck. Thus, it is no longer necessary to weaken the deck by boring and countersinking four through holes for fixing each base plate of the truck.
To this end, the reinforcements of the skateboard deck according to one of the embodiments of the invention are pierced with a bore whose axis forms, together with the plane of the deck, an angle other than a right angle. This bore is used for the passage of the kingpin bolt of the truck.
In other words, this includes using the lower surface layer of the deck itself to mount the hanger without having to use a base plate, as is currently the case. This feature of the invention is to provide the deck, on its lower portion and in the area of the trucks, with a shape that guarantees the functions that are usually carried out by the base plate of the truck, i.e., ensuring the support of the upper elastomeric buffer and the receiving of the end of the pivot of the hanger in a pivot cup provided in the lower surface of the deck.
In one embodiment of the invention, the lower surface layer serves as a base plate, and the fixing of the truck, comprised in this case by the axle and the hanger only, is obtained by the kingpin bolt.
In another embodiment of the invention, the base plate of the truck is integrated within the deck itself during the gluing/pressing of the various plies to one another.
In yet another embodiment of the invention, the base plate only includes the boss portion, which is extended toward the end of the deck so as to constitute a slider. This half base plate is fixed directly to the deck during the gluing of the plies. It can also be glued after the deck is completely finished. Regardless of the method selected, the fixing of the base plate does not require a plurality of fixing screws that extend through and weaken the deck.
The invention also relates to a multi-layered deck including reinforcements, one of the portions of which projects and extends through the lower surface layer, such that the projecting portion serves as a slider.